Summary of the IMS Tech Day on Options for 
Porsche IMS bearing Replacement 

Summary of IMS Tech Day-- IMS Bearing Options

We covered a great deal of information at the IMS Tech Event, I wanted to follow up with a short, written recap for those who may have missed the event, as well as those who walked away with too much information all at once that left their heads spinning.  So here is a little something.

Early Signs of a Failing IMS

One common early signs of a problem is metal in your oil so every oil change you want your mechanic to inspect the filter for ferrous metal.  Another sign is a leak between the gearbox and engine which could be a leaking RMS (rear main seal) or IMS flange.  Third sign and perhaps most scary is the CEL (check engine light) involving camshaft deviation—this means that the cam timing is operating outside of acceptable parameters.  One very important thing to also note is that you can have a failing IMS with absolutely NO symptoms.  I had a customer with a RUF who had no symptoms but just wanted to replace the IMS as a preventative measure.  This car had no symptoms but upon analysis of the original bearing was at a stage 2 level failure and closer to catastrophic engine failure than anyone wants to think about. 

There are 3 Types of OEM bearings

Now you need to know what type of bearing you have and what options are available.  There are three types of OEM bearing designs: double row (MY 1998-mid2000), single row (MY mid2000-mid2005), and the “big bearing” (MY mid2005-2008).  These years give a guide as to what bearing you may have, but sometimes this rule of thumb does not hold true.  The only definitive way is to remove the gearbox and identify the IMS flange.

The Cause of the IMS Failure

According to the class action lawsuit, the signal row bearings have been deemed defective and yes, but that is really only partly true.  The cause of IMS failure has been accepted by most independent Porsche specialists to be due to oil leaking past the outer seal into the original IMS bearing, washing away the permanent grease leaving the bearings susceptible to heat and friction.  How does this happen?  High levels of acid in the oil due to extended oil changes compromise the seals.  But this happens in both single and double row bearings.  Not intended to strike unnecessary fear into anyone, but the only difference between the different types of bearings is the design, not the materials.  If the seals get compromised in the signal row, they also get compromise in the double row.  So, then what is the answer?  There are really two main approaches: maintenance or a permanent fix. 

Under the topic of maintenance:

1.) Change your oil.  I recommend at least twice a year.   No matter how little you drive.  Acid levels in the oil breakdown seals, not just IMS bearing seals, but other seals.  Frequent oil change intervals are the cheapest insurance you can buy.

2.) LN Engineering has developed  “The Guardian” which is a magnetic drain plug with a switch on the dash that gives off a light and an audible tone when metal is detected on the drain bolt. (

3.) LN Engineering also developed the Billet Washable Oil Filter which is designed to trap more FOD (foreign object debris) than standard filter.  These products are more directed towards detection and offer limited prevention.  (

IMS Bearing Options- single row, double row and big bearing

For greater security, or at least piece of mind, against a failing IMS, you may want to begin thinking about addressing the IMS bearing, especially if you are near clutch replacement.  Since the gearbox and clutch are removed, you might as well consider the IMS bearing (kits range from $165-$1725) and RMS (rear main engine oil seal $30).  There are also additional parts necessary, but nominal.

Note, there are replacement bearings that have a service life and there are some replacement bearings that are deemed permanent fixes.  The permanent fixes involve direct lubrication from various points in the engine oil supply.

What is available for the single and double row (1998-mid2005)

  • LN Engineering retrofit replacement bearing- open bearing with ceramic hybrid bearings which are harder than OEM and allows for splash lubrication (  The LN Engineering IMS retro fit has a recommended service life and is expected to be replaced at specific intervals (single row 4yrs/50K miles, double row 6yrs/75K miles).

  • Pelican Parts replacement bearing- sealed bearing similar to OEM (  The Pelican Parts replacement bearing is also intended to be replaced at specific intervals (30K miles).

  • Direct Oil Feed (DOF) Flange- replaces the original flange with a IMS flange that feeds oil directly on the bearing.  The DOF offers choice of steel or ceramic replacement bearings for the single or double row bearings ( The DOF is intended to be a permanent fix because it provides an extra level of lubrication.  The DOF video on oil feed can be viewed at:

  • EPS Cylindrical Bearing with oil feed- instead of a roller ball bearing EPS uses a cylindrical roller which is intended to distribute the load better.  The EPS cylindrical bearing also offers direct pressure feed lubrication.  This also is considered a permanent fix and can be viewed at:

In addition to the above there are a few products that have been developed but ONLY available for the single row bearing:

Currently there is only one option available for the “big bearing” (mid 2005-2008).  
The Direct Oil Feed by TuneRS.  The procedure entails removing the outer seal of big bearing and replaces the original flange with direct oil feeding flange.  The original bearing is still being used but now has direct oil feeding on to the bearing providing constant lubrication.

Most of these products run advertisements in the Panorama or you can check out their websites: LN Engineering, Pelican Parts, Direct Oil Feed by TuneRS, and EPS by Vertex Auto.  I have attempted to provide insightful links to help you further understand the specifications of each option so that you can choose the option that suits your needs best.  Also, here is a helpful chart with some relevant specifics.  To my knowledge, this is the most update information available; however, this is a field that is changing daily. 

 Manufacturer and Type of Bearing Fit  Expected Life Warranty  Lubrication 
 Pelican Parts single & double  30K miles  1 year  sealed bearing 
 LN Single Row Retrofit single  4yrs/50K miles  30 days  splash 
LN Double Row Retrofit  double  6yrs/75K miles 30 days  splash   
LN Single Row Pro  single  6yrs/75K miles  30 days  splash   
LN Solution  single  permanent  30 days  pressure fed oil   

 DOF by TuneRS single, double & big  permanent  lifetime on flange  pressure fed oil   
 Vertex Auto EPS Cylindrical single & double  permanent  5 years  pressure fed oil